Linearly movable gate mechanism

ABSTRACT

A gate mechanism for controlling flow of material from the outlet of a bottom pour vessel. The gate is supported on springpressed antifriction rollers, and moves linearly between pouring, throttling and closed positions.

[ Oct. 16, 1973 United States Patent 1191 Cramer et al.

222/DIG. 7

222/DIG. 7

77 on DD Mfl 22 22 [5 LINEARLY MOVABLE GATE MECHANISM 3,618,834 11/1971Shapland [75] Inventors: Fred C. Cramer, Scott Twp., 23:82 AlleghenyCounty; Calvin Kelly, 3,511,471 5/1970 Franklin Twp., WestmorelandCounty, both of Pa.

[73] Assignee: United States Steel Corporation,

Primary ExaminerRobert B. Reeves Assistant Examiner-David A. Scherbel Ptt b P l s urgh a Attorney-Wa1ter P. Wood [22] Filed: May 10, 1972 [21]Appl. No.: 251,990

ABSTRACT moves linearly between pouring, throttling and closedpositions.

.. 222/D1G. 7 2 Claims, 3 Drawing Figures PAIENIEDum 15 ms 3.765.579

SHEET 1 0F 3 PATENTED Hill 16 I975 SHEET 30F 3 m mam LINEARLY MOVABLEGATE MECHANISM This invention relates to an improved linearly movablegate mechanism for controlling flow of material from a bottompourvessel.

Although our invention is not thus limited, our gate mechanism isparticularly useful as applied to vessels for pouring liquid metal, forexample a ladle or a tundish. Such vessels have an outlet in the bottomwall through which liquid metal is poured into a receiving vessel. It isknown to equip this type of pouring vessel with a linearly movable gatemounted on the underside of the bottom wall for controlling flow ofmetal through the outlet. The usual practice has been to press the gatefirmly against the vessel bottom with springs to prevent metal fromleaking into the crevice therebetween, where it would otherwise solidifyas a tin. In previous constructions a variety of means have been usedfor supporting such gates, for example, spring-pressed levers as shownin Shapland U.S. Pat. No. 3,352,465, a fixed but removable cover asshown in Fichera US. Pat. No. 3,454,201, or graphite blocks as shown inGrosko US. Pat. No. 3,480,186. Rotatable gates also are known, and havebeen supported in a variety of ways, at least one of which includes ballbearings as shown in Rossi US. Pat. No. 3,511,471.

An object of our invention is to provide an improved gate mechanism inwhich a linearly movable gate is supported on spring-pressedantifriction rollers.

A further object is to provide improved antifriction roller support fora linearly movable gate in which the rollers are spring-pressed andconstructed to withstand the severe operating conditions necessarilyencountered in pouring liquid metal.

In the drawings:

FIG. 1 is a top plan view, partly in section, of our improved gatemechanism;

FIG. 2 is a longitudinal section on line lI-Il of FIG. 1; and

FIG. 3 is a cross section' on line Ill-III of FIG. 1.

FIGS. 2 and 3 show the lower portion of a conventional bottom-pourvessel which has a nozzle 12 in its bottom wall. A mounting plate 13 isattached to the bottom wall with bolts 14. The mounting plate has anopening 15 through which the lower end of nozzle 12 projects in theusual fashion. The mounting plate and parts carried thereby form anassembly which can be installed on the vessel or removed as a unit.

The gate mechanism illustrated includes a rectangular supporting frame16 which depends from the mounting plate 13 and is hinged thereto tofacilitate replacement of parts. Frame 16 includes rigidly connectedside members 17 and 17a and transverse members 18, 18a and 18b. Theright edge (FIG. 3) of the mounting plate 13 carries a plurality ofspaced-apart pairs of hinge elements 19, and both edges carry aplurality of pivot blocks 20. The outer face of the side member 17 atthe right of frame 16 carries hinge blocks 21, each of which is receivedbetween a different pair of hinge elements 19 and hinged thereto on pins22. Respective eyebolts 23 are pivoted to blocks and received inbifurcated lugs 24 carried by the outer faces of both side members 17and 17a. Nuts 25 are threadedly engaged with the lower ends of theeyebolts to hold the frame in its operative position. When the eyeboltsare released from the lugs, the frame opens downwardly about its hingedconnection to the mounting plate.

In accordance with our invention, respective elongated spring housings30 are bolted to the inner faces of both side members 17 and 17a. Eachhousing 30 has a plurality of vertical bores 31 and tapped counterbores32 at the lower ends of the bores. Respective retainer caps 33 arethreadedly engaged with the counterbores and carry integral wrench heads34 at their lower faces. Respective plugs 35 and compression springs 36are housed within the bores and counterbores. The springs bear againstthe retainer caps 33 and plugs 35 and thus urge the plugs upwardly. Theplugs have external shoulders 37 which can abut corresponding internalshoulders at the tops of the counterbores to limit upward movement ofthe plugs. Each plug carries a respective opposed pair ofhigh-temperature spherical roller bearings 38 in which a hardened steelroller 39 is journaled on a hardened steel shaft 40. The upper portionsof the plugs 35 and rollers 39 protrude above the upper faces of thespring housings 30.

A rectangular metal gate carrier 43 is supported on rollers 39 forlinear movement. A pusher bar 44 is attached to the right end of thecarrier 43 (FIGS. 1 and 2). The transverse member 18 at the right offrame 16 carries a double-acting fluid-pressure cylinder 45 whichcontains a reciprocable piston and piston rod 46. The end of the pistonrod is attached to the pusher bar 44 through a pin 47. The transversemembers 18a and 18b of the frame 16 have openings 48 to accommodate thecarrier 43.

The upper face of the carrier 43 has a flange 49 which removablyreceives a gate 50 formed of a metal tray and a refractory body. Thegate illustrated includes a pouring tube 51 which depends through anopening 52 in the carrier 43. The upper face of gate 50 bears against arefractory top plate 53 which is fixed within frame 16 beneath themounting plate 13. The top plate is held in place by set screws 54threadedly engaged with the transverse members 18a and 18b. The topplate has an orifice 55 aligned with the opening in nozzle l2. Suitablehigh-temperature gaskets 56 and 57 are interposed between the gate andcarrier 43 and between the top plate 53 and mounting plate 13. The gate50 and its pouring tube 51 have a continuous opening 58 which can bealigned with orifice to permit pouring, partially aligned to throttlethe pouring stream, or moved out of alignment to close off pouring. Thegate 50 illustrated has a convex upper surface, and the top plate 53 amating concave lower surface as described and claimed in applicationSer. No. 244,518 filed Apr. 17, 1972 by the present co-inventor Kelly.This feature is desirable in preventing warping of the gate, but isoptional for the present invention.

A heat shield 60 is bolted to the underside of frame 16 and has anelongated slot 61 which accommodates the pouring tube 51. A splashshield 62 is slidably supported on the upper face of the heat shield 60to cover the slot 61. The splash shield has an opening 63 which receivesthe pouring tube. The parts within the spring housing 30 are furtherprotected from excessive heat by an air-cooling system. The side framemembers 17 and 17a have air ducts 64 to which air lines 65 are connectedthrough suitable fittings 66. Passages 67 afford communication betweenthe ducts 64 and the counterbores 32 in the spring housings.

In operation, the cylinder 45 can be actuated to move gate 50 linearlyto open, closed, or throttling positions, as already explained. Bothedges of the gate carrier 43 ride on antifriction rollers 39 whichenable the carrier to move easily between the different gate positions.The springs 36 urge the rollers into contact with the bottom of thecarrier and in turn urge the upper face of the gate into close-fittingcontact with the top plate 53. The parts are protected from excessiveheat by the shielding and air cooling systems.

From the foregoing description, it is seen that our invention affords asimple practical mechanism for supporting and moving a gate. The use ofrollers on which the gate carrier rides assures that the gate alwaysmoves easily without binding.

We claim:

1. In a gate mechanism for use on a bottom-pour vessel to control flowof material through an outlet in the vessel bottom, said mechanismcomprising:

a mounting plate adapted to be fixed to the vessel bottom and having anorifice to be aligned with the vessel outlet;

a frame hinged to said mounting plate and depending therefrom;

means for releasably holding said frame in a fixed position beneath saidmounting plate;

a pair of spaced-apart elongated spring housings carried by the insideof said frame at opposite sides of said orifice, each of which housingshas a plurality of bores; respective springs housed within said bores;

said frame having passages for introducing cooling air to said bores;

a carrier supported above said housings;

a gate mounted within said carrier;

a top plate fixed within said frame beneath said mounting plate andagainst which said gate bears; and

motive means connected with said carrier for linearly moving saidcarrier and said gate with respect to said housings and said top plate;

the combination therewith of improved means supporting said carrier onsaid housings, said supporting means comprising:

respective vertically movable plugs housed within said bores and urgedupwardly by said springs;

respective opposed pairs of high-temperature spherical roller bearingscarried by each of said plugs; and

respective hardened steel rollers journaled in each pair of saidbearings, said rollers protruding above said housings, said carrierriding on said rollers.

2. A combination as defined in claim 1 in which the lower ends of saidbores have counterbores with a downwardly facing shoulder at the end ofthe counterbore, and said plugs have upwardly facing shoulderscooperable with said downwardly facing shoulders to limit upwardmovement of said plugs and rollers.

1. In a gate mechanism for use on a bottom-pour vessel to control flowof material through an outlet in the vessel bottom, said mechanismcomprising: a mounting plate adapted to be fixed to the vessel bottomand having an orifice to be aligned with the vessel outlet; a framehinged to said mounting plate and depending therefrom; means forreleasably holding said frame in a fixed position beneath said mountingplate; a pair of spaced-apart elongated spring housings carried by theinside of said frame at opposite sides of said orifice, each of whichhousings has a plurality of bores; respective springs housed within saidbores; said frame having passages for introducing cooling air to saidbores; a carrier supported above said housings; a gate mounted withinsaid carrier; a top plate fixed within said frame beneath said mountingplate and against which said gate bears; and motive means connected withsaid carrier for linearly moving said carrier and said gate with respectto said housings and said top plate; the combination therewith ofimproved means supporting said carrier on said housings, said supportingmeans comprising: respective vertically movable plugs housed within saidbores and urged upwardly by said springs; respective opposed pairs ofhigh-temperature spherical roller bearings carried by each of saidplugs; and respective hardened steel rollers journaled in each pair ofsaid bearings, said rollers protruding above said housings, said carrierriding on said rollers.
 2. A combination as defined in claim 1 in whichthe lower ends of said bores have counterbores with a downwardly facingshoulder at the end of the counterbore, and said plugs have upwardlyfacing shoulders cooperable with said downwardly facing shoulders tolimit upward movement of said plugs and rollers.